A new report by the U.N.’s Intergovernmental Panel on Climate Change has deemed that humans have been the driving force behind climate change since 1950, and that it will require significant action to halt the warming.

The report, which is known as AR5, will be released in stages over the next 14 months; the first portion was published in Stockholm on Friday morning. Authored by more than 840 scientists, the report determines that climate change is “unequivocal” and that its authors are 95% certain that it’s due to human action. When presenting the report, IPCC co-chair Qin Dahe said, “Our assessment of the science finds that the atmosphere and ocean have warmed, the amount of snow and ice has diminished, the global mean sea level has risen and that concentrations of greenhouse gases have increased.”

The report also goes on to warn that halting global warming will require “substantial and sustained reductions of greenhouse gas emissions,” reports the BBC.

U.S. Secretary of State John Kerry has issued a statement, reports the Guardian, in response to the report saying, “Boil down the IPCC report and here’s what you find: Climate change is real, it’s happening now, human beings are the cause of this transformation, and only action by human beings can save the world from its worst impacts. This isn’t a run of the mill report to be dumped in a filing cabinet. This isn’t a political document produced by politicians. It’s science.”

Meanwhile, the EU’s Commissioner for Climate Action had a more blunt reaction to the report’s conclusions, tweeting: